64 Natural History Bulletin. 



M. MULTILINEATA. Say. 



Very common in rather low places throughout the state, and 

 exceedingly variable. The color is often a uniform brown or 

 in other cases a deep reddish-brown, the latter especially in 

 specimens taken in swamps in the open prairie in which "bog- 

 iron ore" has accumulated. Specimens from such places are 

 usually also much smaller, but heavier proportionally than 

 forms occuring in timbered regions. Some of the smaller 

 heavier specimens have a rudimentary parietal tooth. The 

 variation in diameter is from fifteen to twenty-seven mm. It is 

 also found in the Loess. The fossils vary from twelve and 

 one-half to sixteen mm., in diameter, the total range of varia- 

 tion in the species being from twelve and one-half to twenty- 

 seven mm! 



M. CLAUSA. — Say. 



Rather common under logs and leaves on high timber- 

 lands. 

 M. PROFUNDA. — Say. 



Very common on steep, shaded hillsides. Specimens with- 

 out bands are not uncommon. A reversed specimen was 

 found by us near Iowa City. 



Subgenus Strohila. — Morse. 



S. LABYRINTHICA. Say. 



Not rare in high shaded places. Formerly this species was 

 very common near Iowa City, but is now quite rare. 



Subgenus Vallonia. — Risso. 



V. PULCHELLA. Mucll. 



Very common in yards under boards, etc. It is also a Loess 

 fossil. 



V. PULCHELLA, VaV COSTATA. Mucll. 



Quite common on dry, rocky hillsides and steep bluffs. It 

 seems to be quite constant in its characters. 



